That's not a misconception I share. I understand Mozilla can and should make money to further its mission.
But unlike a for-profit, making money isn't the mission of Mozilla. So needing to make money can't be used as a justification for doing naughty things against the public good.
And money it makes, in the hundred of millions, for serving its users to the worst known worldwide privacy offender, collecting and profiling user to sell advertising.
The "good" non profit charity foundation is governing the "evil" for profit corporation giving away users to the worst opponent of the mission of the charity. Quite a contradiction in this.
Some people cry "free speech violation" but they can endorse a candidate, they just need to give up their tax privileges. This is why the ACLU is split into two parts. One you can donate to and get tax dedications for, but the other is their lobbying arm, and therefore cannot allow tax deductions for their donors.